Fuel-burner-control system



April 14, 1931. P. F. SHIVERS FUEL BURNER CONTROL SYSTEM Filed y 5, 19262 Sheets-Sheet 2 m ww NQ QM R Lwzfiwzau 3E 336 hw=3-=u 3E :35 $3 35.5and NM .1 ab M m *N QM NN R EN h 3.1 9 .55 \r mum WW, nQEL EQ WW QT: 55%visas MW r N i v .WN

. 6 m W A n 00 f NW 5 y B ONI$ Patented Apr. 14, 1931 UNITED STATESPATENT OFFICE PAUL F. SHIVERS, OF WABASH, INDIANA, ASSIGNOR, BY MESNEASSIGNMENTS, TO MINNEAPOLIS-HONEYWELL REGULATOR COMPANY, OF MINNEAPOLIS,MINNESOTA,

A CORPORATION OF DELAWARE FUEIrBURNER-CONTROL SYSTEM Application filedMay 3,

In the installation of oil burners, especially those of the householdtype where constant attention is not possible, it is necessary toprovide means by which the flow of fuel will be automatically cut of!either in case of failure of initial ignition, or in case of failure ofcombustion, or in case the operater attempts to render portions of theapparatus inoperative.

The object of my present invention is, therefore, to provide a simpleandefiicient mechanism by which the above-stated desirable results maybe attained.

The-accompanying drawings illustrate my invention. Fig. 1 is adiagrammatic illustration of an embodiment of my invention; and Fig. 2is a diagram of a modification. In the drawings 10 indicates a fuelburner and 11 an electrically actuated controller by.

means of which delivery of fuel to burner 10 is controlled. The burner10 and controller ll will, of course, be of a type suitable to handlethe desired fuel, the details forming no part of my invention exceptthat the controller 11 is electrically-actuated. This ele- 'ment 11 may,as will be readily apparent, be a motor driving a fuel pump delivery tothe burner. or an actuator for a valve which will control delivery of afuel to the burner, etc.

A 'rcuit breaker 1-2, of a type to be infiuenc d by the presence orabsence of combustion at burner 10, comprises terminals 13 and 14. Thiselement 12 may conveniently be a thermostat of ordinary form or may bean element responding to variations in'light or pressure induced bycombustion conditions.

A most satisfactory element for this purpose is the thermostat shown inmy pending application, Serial No. 70,808 filed November 23. 1925. inwhich making or breaking of the circuit is accomplished promptly uponreversal of temperature conditions irrespec:

An electromagnetic switch-actuating mocoil 37.

1926. Serial No. 106,274.

tor 18 is capable of actuating a switch 19. This actuating motor and itsswitch may vary considerably as to form and construction but must becapable of being stalled without injury to its circuits. In the diagramthe motor is of the shaded-pole induction type, without contact brushesor cutouts and comprises the shaded-poles 20, rotor 21 and pole windings22 and therefore is capable of being stalled without injury.

Geared to rotor 20 is a plunger 23 biased in-one direction by a spring24 capable of reversely rotating the rotor in the absence of current inthe field coils. Plunger 23 actuates two snap-switch elements 25 and 26.Element 25 may make or break connection between two terminals 27 and 28.Element 26 may alternately make or break connection between the twopairs of terminals 29, 3O

cooperating terminals 34 and 35 which are biased open and arenormallyheld in contact by the thermal element 36 arranged within the influenceof an electric heating In order that the elements 15 and 18 may below-voltage elements, I provide a transformer 40 comprising aprimarywinding 41 and a secondary winding 42.

The electrical connections are as follows: wire 51 from 16 to 42; wire52 from 42 to a. wire 53 connecting 31 and 37; wire 54 and 37 to a wire55 connecting one end of coils 22 with 13; wire 56 from 1 4 to 30 and32; wire 57 from 17 to coil 22; wire 58 from wire 57 to 29; wire 59 from35 to 27; wire 60 from 11 to line; and wire 61 from 60 to 41.

Thus far the connections are the same in Figs. 1 and 2. In Fig. 1 thefurther connections are: wire 62 from28 to 11; wire 63 from 41,to 59 andwire 64 from 34 to line.

In Fig. 2 the further connections are: wire 62 from 28 to line; wire 63'from 41 to line and wire 64 from 34 to 11.

The difference between Figs. 1 and 2 is that in Fig. 1 terminals 34 and35 control both elements 11 and 18, while in Fig. 2 terminals 34 and 35are in circuit only with 11.

For convenience in further description and in the claims element 11 willbe called the fuel controller; element 12 the circuit- I action relaymay be of any construction such that a flow of current in its circuit,if and when maintained for a suflicient time and of suflicient volume,will cause attainment of an abnormal circuit relation.

Referring now to Fig. 1, the operation will be as follows, the partsbeing, as shown, in the warm position, where no action of the burner isdesired.

A potential exists in the circuit line, 60, 61, 41, 63, 59, 35, 34, 64,line.

Upon a cooling of the room thermostat a circuit 16, 51, 2, 52, 53, 37,54, 55, 22, 57, 17, 16 is established and rotor 21 moves to shift thefuel controller switch 25 into contact with terminals 27, 28 and thesafety switch 26 into contact with terminals 31, 32.

Switch 25 establishes the circuit, line, 64, 34,,

35, 59, 27, 25, 28, 62, 11, 60 and line, thus actuating the fuelcontroller 11 so that there will be fuel delivery to burner 10.

The flow of current through 37 causes a heating of the thermal element36 which, in time, will cause a separation of terminals 34 and 35, ifthere has been a failure of ignition and the combustion indicator hasnot been warmed sufliciently to close contacts 13,

14. An actuation of the delayed-action relay breaks the energizingcircuit for the fuel controller 11 and also breaks the primary circuitof the transformer thus de-energizing the field of the switch actuatorand permitting spring 24 to reverse the switch 25 and thus break thecircuit of the fuel controller at 'a second point 27-28. Under suchcircumstances fuel delivery may not be resumed until the delayed-actionrelay has been reset by placing element 36 in position to hold terminals34 and 35 in contact.

In Fig. 2 the primary coil 40 of the transformer, is always energizedand the separation of terminals 34 and 35 directly breaks the circuit ofthe fuelcontroller 11, switch 2? remaining in position bridgingterminals 2 28.

If initial ignition has ocurred in proper time terminals 13 and 14 willbe caused to contact whereupon circuit is established through 31 and 32to short out the heater 37 as follows: 14, 56, 32, 26, 31, 53, 52, 42,51, 16, 17. 57,- 22, 55, 13, 14, thus maintaining current in the switchactuator and thus itch 25.

a for said motor,

enever the remote control switch (room thermostat) opens the break at16, 17 releases the rotor 21 and permits spring 24 to break the circuitof the fuel controller by moving switch 25 into the position shown.

In case of a failure of combustion at any time (as distinguished fromfailure of ignition) a circuit break occurs at 13 14, thus breaking theshunt circuit around the heating element 37, which, after a suitableperiod,-will flex the thermal element 36 to permit the contact points3435 to separate, breaking the burner motor circuit.

Some operators or users are inclined to attempt to eliminate the circuitbreaker 12 from the system by placing a short across terminals 13-14,but in my present device any such attempt serves, upon a closing of theroom thermostat, to immediately cause a break in the fuel controllercircuit at 3435 in the: following manner. Switch 26 being in its normalposition bridging contacts 29, 30, a connection between wires 55 and 56establishes circuit 16, 51,42, 52, 53, 37, 55, 56,

causing it to be heated very quickly, result- 1 ing in a break at 34-35and requiring manual re-establishment of contact between 34 and 35.

If contacts 13 and 14 should be permanently connected or shorted whilethe burner was working there would, at first, be no action but, when theroom'thermostat warmed up 'so as to cause a break at 1617 there wouldresult a break in the fuel controller circuit at 27-28, in the manneralready described.

Then, when the room thermostat cooled down and reestablished contact at1617 the full secondary current would be delivered through the heater37, as already described, and the safety break at 34-35 would promptlyoccur. 3 i

It will of course be readily understood that an automatic ignitiondevice may be readily provided either of such character as to giveacontinuous spark throughout the entire period of operation or such as tobe i 1. In a control system for fuel burners, a

burner, a main electric motor controlling operation of saidburnen'anenergizing circuit a switch-actuatmg electric motor, a reci rocating.switch-actuating member control ing the starting and stopping of saidmain motor actuated in one the switch-actuating motor, a remote switchin circuit with said heating element, switching means in circuit withsaid remote switch and controlled by combustion conditions adjacent theburner, and means for varying the effect of said switching means on saidheating b element.

2. The combination with a fuel burner and electrically actuated fuelsupplying means therefor, of an electric motor, an energizing circuittherefor, a switch for controllin said v circuit, an electric actuatingelement in series with said motor in said circuit, a timing switchoperable thereby and connected to break the energizing circuit for saidfuel'supplying means, a reciprocable element actuated in one directionby said motor and constantly biased for movement in the oppositedirection, switching means controlled by combustion conditions adjacentthe burner, and means controlled by said reciprocable element forvarying the effect of said switching means on said electric actuatingelement.

3. In a control system for fuel burners, a

burner motor, an energizing circuit therefor including a switch and adelayed action circuit breaker, a transformer having its primary inseries with the circuit breaker, a room thermostat in series with thesecondary of the transformer, a supplemental electric motor having itsenergizing circuit connected to the room thermostat and trans-- formersecondary, an electric actuating element for said circuit breaker,electric connections between the actuating element and the supplementalmotor circuit, a combustion controlled circuit breaker arranged to shuntthe actuating element in the presence of combustion, a safety switch,and means actuated by said supplemental motor to shift the burner switchand to shift the safety switch for varying the effect of said combustioncontrolled circuit breaker on said actuating element. v i

4. In a control system for fuel burners, a burner motor circuitincluding a switch and a delayed action circuit-breaker comprising anelectric heating element, a transformer, a room thermostat in serieswith the secondary of the transformer, a supplemental electric motorhaving its energizing circuit connected to the room thermostat andtransformer secondary, electric connections between the heating elementand the supplemental motor circuit, a combustion-controlledcircuittrolling breaker arranged to'shunt the heating element inthe'presence of combustion, a twoposition safety switch in circuit inelther osition with the heating element and combustion-controlledcircuit-breaker and shorting the supplemental motor in an abnormalclosed condition of said combustion controlled circuit-breaker, andmeans actuated by said supplemental motor to shift the burner switch andsafety switch.

5. In a control system for fuel burners, a burner motor circuitincluding a switch and a delayed-action circuit-breaker comprising anelectric heating element, a transformer having its primary in serieswith the circuitreaker, a room thermostat in series with the secondaryof the transformer, a supplemental electric motor having its energizingcircuit connected to the room thermostat and transformer secondary,v,electric connections between the heating element and the supplementalmotor circuit, a combustion-controlled circuit-breaker arranged to shuntthe heating element in the presence of combustion, a two-position safetyswitch in circuit in either position with the heating element andcombustion-controlled circuit-breaker and shorting the supplementalmotor in an abnormal closed condition of said circuit-breaker, and meansactuated by said supplemental motor to shift the burner switch andsafety switch.

6. In a control system for fuel burners, the combination of a highvoltage circuit, a low voltage circuit, a motor in the high voltagecircuit for controlling the operation of the burner, a switch actuatingelectric motor in the low voltage circuit, a switch member voperated bysaid switch-actuating motor for controlling the starting and stopping ofthe burner motor, a circuit-breaker in the high voltage circuit andcomprising a thermostatic element and a heater therefor in the lowvoltage circuit, a-circuit breaker in the low voltage circuit of theswitch-actuating motor, and arranged to shunt said heater under certainconditions, and means connected in said low voltage circuit andoperable, under certain conditions, to cause said last mentionedcircuit-breaker to shunt said actuating motor, and a switch to open andclose the low voltage circuit.

7. In a control system for fuel burners, a burner-motor circuitcomprising a fuel-conmotor, a heat-affected circuitbreaker, and acontrolling switch; a low voltage circuit comprising in series, anelectrically-actuated switch motor for actuating said switch, anelectric heater for the said circuitbreaker, and a room thermostat; anormallyopen heat-affected circuit-breaker to be arranged ,within theimmediate heat-effect of the burner; a switch terminal connected to afirst contact of said last-mentioned circuit breaker, a cooperatingswitch terminal 'connected to one terminal of said switch motor and tosaid room thermostat in parallel,

switch means eiiective, when said switch motor is deenergized to connectsaid two switch lished through said switch motor and said heatingelement under the control of said thermostat, and if said last-mentionedcircuit breaker is closed, a circuit is established around said motorand through said heating element under the control of said thermostat; athird switch terminal connected to said first contact of said lastmentioned circuit breaker and a cooperating switch terminal connected tothe other terminal of said switch motor through said heating element,said last-mentioned switch means being effective, when K said switchmotor is energized, to connect said two last-mentioned switch terminalswhereby, ifsaid last-mentioned circuit breaker is open, a circuit isestablished through said motor and said heating element under thecontrol of the room thermostat, and if said lastmentioned circuitbreaker is closed, a circuit is established around said heating elementand through said motor under the control of said room thermostat.

8. In a control system for fuel burners, a high voltage burner-motorcircuit comprising a. fuel-controlling motor, a heat-afi'ected circuitbreaker, anda controlling switch; an

' electrically controlled switch motor for actuating said switch; and alow-voltage circuit comprising a cold-open room thermostat, cold-openheat afi'ected circuit breaker to be arranged within the immediate heateffect of the burner, an electric heater for the first mentioned circuitbreaker, the energizing circuit of the switch motor, and a twopositionswitch actuated by the switch motor, said two-position switch innon-fueldelivery position of the switch motor afi'ording a circuit forthe heater through the second mentioned circuit breaker which will shuntthe switch-motor relative'to the heater and in the fuel deliveryposition of the switch-motor, afiording a circuit through the secondmentioned circuit breaker which will shunt the heater relative to theswitchmotor.

9. In a control system for fuel burners,

a burner motor, a circuit therefor'including a switch and adelayed-action circuit breaker, an electric heating element for saidcircult breaker, a transformer having its pri-' mary in series with thecircuit breaker only, a room theremostat in series with the secondary ofthe transformer, a supplemental electric motor for actuating said switchhaving its energizing circuit connected in series to the roomthermostat, transformer secondary, and the heating element a combustioncontrolled circuit breaker normally open when there is no combustion,switclnng means actuated by said supplemental motor, I

and means so interconnecting the same with the heater, combustioncontrolled circuit breaker and supplemental motor that, when thesupplemental motor is energized operatlWE closing of the combustioncontrolled circuit breaker shunts the heater only and, when thesupplemental motor is deenergized, operative closing of the combustioncontrolled circuit breaker short circuits thesupplemental motor only.

10, Burner control mechanism comprising electrically operated fuelsupplying means; a circuit including said means and including a delayedaction circuit breaker and a main switch; a second circuit including amotor for operating the main switch and an electrically operatedactuator for said delayed action circuit breaker in series, a burnerswitch responsive to temperature conditions adjacent the burner, switchmeans operable by said motor, and means so interconnecting the elementsof the second circuit that the positions of said last mentioned switchmeans and said burner switch upon energization of said second circuitdetermine the rate of current flow through said electrically operatedactuator.

11. Burner control mechanism comprising electrically" operated fuelsupplying means; a circuit including said means and including a delayedaction circuit breaker and a. main switch; a second circuit including athermostatically operated switch, a motor for operating the main switch,and an electrically operated actuator for said delayed action circuitbreaker in series, and a switch responsive to temperature conditionsadjacent the burner; a third switch normally shiftab-le in response tothe position of said thermostatically operated switch, and means sointerconnecting the elements of said second circuit that the operativecondition of said burner-affected switch at the time of closure of saidthermostatic switchdetermines the rate of current flow through saidelectrically operated actuator.

12. Burner control mechanism comprising electrically operatedfuel-supplying means; a circuit including said means and including adelayed-action circuit breaker and a main switch; a second circuitincluding a motor for operating the main switch and an electricallyoperated actuator for said delayed-action circuit breaker in series, aswitch responsive to temperature conditions adjacent the burner, meansoperable by said switch actuating motor and means interconnectingthe'elements of said second circuit to cause closure said main switch isopen.

i a burner; a main circuit including electricalopening saidcircuitbreaker,

ly operated means for supplying fuel to said .burner, a circuit breakerand a circuit controller; a second circuit normally in control of saidmain circuit throu h said controller; means for opening and c osing saidsecond circuit, an electric actuator connected in said second circuitand operable, upon energization, to open'said circuit breaker, meansre-- sponsive to temperature conditions adjacent said burner forshunting said actuator, and means so connected in the second circuitthat operative closure of said burnerresponsive means in advance ofenergization of said second circuit to energize said main circuit willrender said burner responsive means ineffective to shunt said actuator.a

14. Burner control mechanism comprising a main circuit includingelectrically operated fuel-supplying means, a delayed action circuitbreaker, and a main switch; a room thermostat; a second circuit underthe control of said thermostat and including a motor for actuating saidmain switch and an actuator for said delayed-action circuit breaker inseries therewith; a switch positioned to be affected by conditionsadjacent said burner;

ing direction and continuously biased in opening direction, a combustioncontrolled switch responsive to combustion conditions of the burner openwhen cold, a two-position switch in series with said combustloncontrolled switch under the influence of the switch actuating motor toone of its circuit closing positions and continuously biased toward 1tsother circuit closing position, a circuit breaker in said energizingcircuit, an electric actuator acting when energized to open saidbreaker, a switch responsive to temperatures at a remote point, andelectrical connections between an energy source, the combustioncontrolled switch, the two-position switch, the remote switch, theactuator, and the switch actuating motor, whereby closure of the remoteswitch subsequent to an o erat1ve closure of the combustion controlleswitch will energize the actuator without operatively energizing theswitch actuating motor.

In witness whereof, I have hereunto set my hand at Wabash, Indiana, this30th day of April, A. D. one thousand nine hundred and twenty-six.

PAUL F. SHIVERS.

means controlled by said switch actuating motor and means soconnectingsaid last'men- I tloned switch and last name second-circuit that saidlast named means alternately connects said last mentioned switch toshunt said actuator and to shunt said switch actuating motor.

15. In a'burner "control, a two-position switch continuously biased toone'of its cir cuit closing positions, a switch responsive to combustionconditions in series with said two position switch in each of itspositions, a switch actuating electric motor acting, when suflicientlyenergized, to shift said two-position switch to its other circuitclosing position, a switch responsive to temperature conditions at aremote point closed when cold, electric fuel sup breaker, anelectrically operated actuator for.

an energizin c1rcuit-for the fuel supplying means inclu ing said circuitbreaker and a main switch operable by said switch actuating motor, and

means in said plying means, a circuit .c rcuit connections including theremote 'switch, the actuator,-

the switch actuating motor, the two-position switch, and the combustioncontrolled switch, whereby closure of the-remote switch subsequent to anoperative closure of the combustion controlled switch will energize theactuator without operatively energizmg the switch actuating motor.

16. In a control system for fuel burners, a

I burner, electrically o erated means controlling operation of saiburner,- circuit for sald means, electric motor, a switch msaidenergizing cira switch actuating cut under the influence of said motorin closan energizing

